https://www.gov.uk/government/news/pms-european-council-press-statement-20-october-2017
https://www.gov.uk/government/news/pms-open-letter-to-eu-citizens-in-the-uk
https://www.europarl.europa.eu/doceo/document/B-9-2020-0098_EN.html?utm_source=POLITICO.EU&utm_campaign=3e49ba2509-EMAIL_CAMPAIGN_2020_02_13_05_53&utm_medium=email&utm_term=0_10959edeb5-3e49ba2509-190380769
https://www.instituteforgovernment.org.uk/sites/default/files/publications/negotiating-brexit-preparing-talks-uk-future-relationship-eu-FINAL_1.pdf